hackage2nix: Correctly flag broken Haskell packages

I added pkgs.haskell.packages.ghc901.haskell-language-server to the available packages in my Nix configuration, and get a build error (see below). Afterwards, I did some research and found that haskell-language-server is not yet available for GHC 9.0.1, so pkgs.haskell.packages.ghc901.haskell-language-server is correctly broken but not labeled as broken.

I am not familiar with the Haskell pipeline of Nixpkgs, but I wanted to ask if it is possible to label broken Haskell packages accordingly? In this case, it would have saved me, and I guess many others, a lot of time.

Please let me know, what you think.

The specific error message:

error: builder for '/nix/store/6wg48vjfrzhpb1k2b6aqvbwnbw2ifml4-ghc-api-compat-8.6.drv' failed with exit code 1;
       last 10 log lines:
       >       - The module 'GHC.Iface.Utils'
       >         is not exported by any suitable package.
       >         It occurs in neither the 'exposed-modules' of this package,
       >         nor any of its 'build-depends' dependencies.
       >       - The module 'GHC.Driver.Packages'
       >         is not exported by any suitable package.
       >         It occurs in neither the 'exposed-modules' of this package,
       >         nor any of its 'build-depends' dependencies.
       >     In the stanza library
       >
       For full logs, run 'nix log /nix/store/6wg48vjfrzhpb1k2b6aqvbwnbw2ifml4-ghc-api-compat-8.6.drv'.
error: 1 dependencies of derivation '/nix/store/5rfswq3vf8dyqkw441y5ywx7qb334zzn-haskell-language-server-1.2.0.0.drv' failed to build
error: 1 dependencies of derivation '/nix/store/8g67r8yzcl2azhz48y8vwmnrbb8arf0j-home-manager-path.drv' failed to build
error: 1 dependencies of derivation '/nix/store/ylys98ijpysjii2pxcw4kj28lz9dv845-home-manager-generation.drv' failed to build

Start by tracing the hackage2nix handling for Haskell packages and the GHC 9.0.1 package set, using the reported haskell-language-server build failure as the reproduction case. Determine how unavailable packages are identified and marked broken, then verify that the package is labeled broken before its dependencies are built.